1. Field of the Invention
This invention relates to an internal combustion engine control system for affecting split engine operation and to valve deactivators used with the intake and exhaust valves of the engine to control its operation.
2. Description of the Prior Art
Internal combustion engines that operate in a split engine mode to achieve fuel economy have been previously developed but have yet to achieve wide commercial usage. Selected cylinders of the engine are deactivated during split engine operation so that no fuel is fed to them but rather is fed only to the other cylinders. Intake and exhaust valve deactivators are utilized to provide this control of the cylinder operation. A V-8 cylinder engine will normally have one or two of its cylinders on each bank rendered inoperative by valve deactivators during the split engine operation to provide four or six cylinder operation and will have all eight of its cylinders functioning during full engine operation. Likewise, a V-6 cylinder engine will have one or two cylinders on one or both of its sides operating during split engine operation for two, three, or four cylinder operation and all six cylinders will function during full engine operation.
The United States Patent of Brown U.S. Pat. No. 3,964,455 discloses a split engine valve deactivator including a movable piston that supports an intermediate portion of the rocker arm of the valve. The piston is located toward the engine from the rocker arm and positioned in an inner position with respect to the engine to locate a push rod end of the rocker arm so that a push rod pivots the rocker arm about a bearing moved by the piston such that a valve actuating end of the rocker arm opens and closes the associated cylinder valve. Positioning of the piston in an outer position with respect to the engine locates the bearing such that telescoping portions of the push rod reciprocate with respect to each other while a lash spring maintains engagement thereof with the push rod and of the rocker arm, the net result being that no pivoting of the rocker arm takes place and hence no valve opening or closing results despite the push rod movement.
See also U.S. Pat. Nos. 2,745,391; 2,955,750; and 3,874,358.